1. Field of the Invention
The present invention relates to an output apparatus suitable for an electronic typewriter or a wordprocessor and, more particularly, to an output apparatus with an underlining function.
2. Description of the Related Art
In conventional mechanical or electric typewriters, when an additional or ornamental character (e.g., an underline or upper line), more particularly, an underline is to be added to a character string to be printed, after printing the character string, a printing head is returned to a desired portion to be underlined, and the underline is superimposed thereon to obtain the underlined character string.
In recent years, a so-called electronic typewriter of an electronic control type using a microprocessor has been developed. In such an electronic typewriter, when an underline is added to a character string to be printed, an underlined character string can be automatically obtained upon use of an automatic underlining function without separately printing the character string and the underline.
In some conventional electronic typewriters with the automatic underlining function, a character and an underline are automatically printed at the same position upon depression of a desired character key. In others, when a return key is depressed, a character string, to which the underline is to be added, is underlined. In such an electronic typewriter, when the automatic underlining function is enabled, the underline is undesirably added to a space upon depression of a space key.
Such an automatic underlining function has an advantage in that even if a character string is constituted by a plurality of words, an underline can be continuously added to the overall character string. conversely, when the space key is depressed to move a printing head to set a margin or tab while the automatic underlining function is enabled, the underline is printed at an unnecessary portion.
For this reason, each time the printing head is moved, an operator must check if the automatic underlining functionis enabled, thus complicating a printing operation.
Not only a print output but also a display output has similar drawbacks. More specifically, when a cursor is moved to set a margin or tab, if the space key is depressed while the automatic underlining funtion is enabled, the underline is displayed undesirably.